SX3008F does not respond to DHCP requests

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SX3008F does not respond to DHCP requests

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SX3008F does not respond to DHCP requests
SX3008F does not respond to DHCP requests
2024-03-23 19:14:23 - last edited 2024-03-26 01:40:42
Model: TL-SX3008F  
Hardware Version:
Firmware Version: Build 20231011 Rel.42220

I have an SX3008F (hardware 1.20 or 1.6 depending on where you look) which is "fresh" in that I…

 

  • …have updated to the latest firmware release (Build 20231011 Rel.42220).
  • …have not done any interesting configuration. For example, the only VLAN is the default.

 

The switch is acting pretty much un-managed — as you would expect — except of course that it knows how to acquire an IP address for itself from a DHCP server and add an entry to its routing table using the gateway offered by that DHCP server.

 

The first thing I want is for the switch to serve DHCP, so I've enabled that and created a pool of private addresses.

 

Some aspects of the pool creation interface are unfamiliar to me — despite my having what I thought was a fairly good understanding of DHCP — so it's possible this is where I have erred.

 

I can see in the DHCP packet statistics that requests are coming in (presumably from the computer on which I am typing right now)… but no responses are going out.

 

I take this to mean that this isn't a matter of the responses going to the wrong place. They simply aren't going anywhere at all because they do not exist.

 

Furthermore, I don't see any way to send them anywhere in particular, so it's difficult to say where they should be allowed to go except perhaps "everywhere", and that clearly isn't happening either.

 

Any hints would be welcome.

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#1
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Re:SX3008F does not respond to DHCP requests-Solution
2024-03-25 03:11:05 - last edited 2024-03-26 01:40:42

Hi @integerpoet 

Thanks for posting in our business forum.

If you have a fair knowledge about VLAN, this article would fix it. Please take a look at this FAQ:

Best Regards! If you are new to the forum, please read: Howto - A Guide to Use Forum Effectively. Read Before You Post. Look for a model? Search your model NOW Official and Beta firmware. NEW features! Subscribe for the latest update!Download Beta Here☚ ☛ ★ Configuration Guide ★ ☚ ☛ ★ Knowledge Base ★ ☚ ☛ ★ Troubleshooting ★ ☚ ● Be kind and nice. ● Stay on the topic. ● Post details. ● Search first. ● Please don't take it for granted. ● No email confidentiality should be violated. ● S/N, MAC, and your true public IP should be mosaiced.
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Re:SX3008F does not respond to DHCP requests-Solution
2024-03-25 03:11:05 - last edited 2024-03-26 01:40:42

Hi @integerpoet 

Thanks for posting in our business forum.

If you have a fair knowledge about VLAN, this article would fix it. Please take a look at this FAQ:

Best Regards! If you are new to the forum, please read: Howto - A Guide to Use Forum Effectively. Read Before You Post. Look for a model? Search your model NOW Official and Beta firmware. NEW features! Subscribe for the latest update!Download Beta Here☚ ☛ ★ Configuration Guide ★ ☚ ☛ ★ Knowledge Base ★ ☚ ☛ ★ Troubleshooting ★ ☚ ● Be kind and nice. ● Stay on the topic. ● Post details. ● Search first. ● Please don't take it for granted. ● No email confidentiality should be violated. ● S/N, MAC, and your true public IP should be mosaiced.
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Re:SX3008F does not respond to DHCP requests
2024-03-26 15:46:59 - last edited 2024-03-26 16:05:48

Thanks. The later parts of that post did help.

 

When I first saw that post, I concluded it must not apply to me. The early parts of the post talked about disabling DHCP on the upstream router. I understand why, but I don't control the upstream router, so I stopped reading the post. I now see how the later parts of that post do apply to me — and I was able to get the DHCP server working.

 

This success now unmasks a problem which I think is similar to this post. It sounds as if I may be able to overcome this issue if my ISP can give me some asurance that my gateway address won't change often. However, it seems I will need to find a way to prevent DHCP requests and/or responses from passing between my VLANs and my ISP. Based on what I have read elsewhere, I am not optiimistic about this.

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Re:SX3008F does not respond to DHCP requests
2024-03-27 02:14:23

Hi @integerpoet 

Thanks for posting in our business forum.

integerpoet wrote

Thanks. The later parts of that post did help.

 

When I first saw that post, I concluded it must not apply to me. The early parts of the post talked about disabling DHCP on the upstream router. I understand why, but I don't control the upstream router, so I stopped reading the post. I now see how the later parts of that post do apply to me — and I was able to get the DHCP server working.

 

This success now unmasks a problem which I think is similar to this post. It sounds as if I may be able to overcome this issue if my ISP can give me some asurance that my gateway address won't change often. However, it seems I will need to find a way to prevent DHCP requests and/or responses from passing between my VLANs and my ISP. Based on what I have read elsewhere, I am not optiimistic about this.

You probably need to add a different router even though this creates a different NAT.

But it will fix the problem like you described that you cannot control the upstream router.

If that's the case, what you can do is limited and you might need to seek some kinds of different unusual solutions to bypass that.

AFAIK, I don't think I can come up with a different approach to this.

Best Regards! If you are new to the forum, please read: Howto - A Guide to Use Forum Effectively. Read Before You Post. Look for a model? Search your model NOW Official and Beta firmware. NEW features! Subscribe for the latest update!Download Beta Here☚ ☛ ★ Configuration Guide ★ ☚ ☛ ★ Knowledge Base ★ ☚ ☛ ★ Troubleshooting ★ ☚ ● Be kind and nice. ● Stay on the topic. ● Post details. ● Search first. ● Please don't take it for granted. ● No email confidentiality should be violated. ● S/N, MAC, and your true public IP should be mosaiced.
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